Properly handle the case where the CheckFloat64Hole becomes a
no-op after RETYPE (because the feedback type is already Number).
We always need to pass the Number restriction type here.

Bug: chromium:895199
Change-Id: I96a949ba35db1e6d35abedddc4507c101d95b716
Reviewed-on: https://chromium-review.googlesource.com/c/1278804Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56622}